What is a particularized implicature?

A particularized implicature is a conversational implicature that is derivable only in a specific context.

Examples (English)

A: What on earth has happened to the roast beef?

B: The dog is looking very happy.

In the above exchange, A will likely derive the implicature "the dog ate the roast beef" from B’s statement. This is due to A’s belief that B is observing the conversational maxim of relation or relevance in the specific context of A’s question.